Network traffic is transmitted over a network, such as the Internet, from a host (e.g., a device capable of receiving data over a network) to another host. Each host uses a specialized piece of hardware commonly referred to as a network interface card (NIC) to access the network. The NIC is a piece of hardware found in a typical computer system that includes functionality to send and receive network traffic. Typically, network traffic is transmitted in the form of packets, where each packet includes a header and a payload. The header includes information regarding the source address, destination address, size, transport protocol used to transmit the packet, and various other identification information associated with the packet of data. The payload includes the actual data to be transmitted from the network to the receiving system. The contents and transmission of the aforementioned packets on the network are typically governed by Transmission Control Protocol (TCP) and Internet Protocol (IP).
Processing network traffic requires significant host resources. To decrease the amount of processing required by the host, specialized hardware has been developed to process packets. The specialized hardware is external to the processor, which initially processes the packet, and typically only supports single threaded processing (i.e., packets are typically not processed in parallel). The specialized hardware typically includes functionality to obtain packets from the processor, perform specific functions on the packet (e.g., calculate checksum, decrypt packet, encrypt packet, and perform processing required by TCP or IP, etc.), and return the processed packets to the processor. In order to use the specialized hardware, two or more additional I/O operations are typically required in order to transfer packets to the specialized hardware and received the processed packets from the specialized hardware.